Using a QSAR computer model to screen mackerel muscle protein fragments, researchers discovered two novel ACE-inhibitory peptides, with PLITT showing strong activity (IC50: 48.73 μM) and excellent stability under heat, pH changes, and salt — making it a candidate for blood pressure-lowering functional foods.
IC50: 48.73 μMthe novel mackerel peptide PLITT's potency for blocking ACE — and it remains stable under high heat, varying pH, and salt conditions relevant to food processing
What the researchers found
The novel mackerel-derived peptide PLITT inhibits ACE with IC50 of 48.73 μM through mixed competitive/non-competitive mechanisms via hydrogen bonding, and remains stable under food processing conditions.
Why it matters
High blood pressure affects nearly half of adults worldwide and is a leading risk factor for heart disease and stroke. Finding stable, food-derived ACE inhibitors means people could potentially lower blood pressure through functional foods or supplements, complementing or even partially replacing pharmaceutical drugs with fewer side effects.
The numbers in context
Two novel peptides identified: LTPFT and PLITT; QSAR model based on 5z-scale metrics; molecular docking confirmed binding mechanisms.
How the study worked
Developed a QSAR model using 5z-scale descriptors to screen mackerel muscle hydrolysates for ACE-inhibitory peptides. Validated top candidates (LTPFT, PLITT) through in silico screening, molecular docking, enzyme kinetics, and stability testing under heat, pH, glucose, NaCl, and metal ion conditions.
Who was studied
In vitro and computational analysis of mackerel muscle hydrolysates
What this study cannot tell us
In vitro and computational study only — no human or animal blood pressure measurements. Whether enough PLITT survives digestion to reach the bloodstream at therapeutic concentrations is unknown. The IC50 of 48.73 μM, while respectable, means significant amounts would need to be consumed for a blood pressure effect.
How to read the evidence
Preliminary — in vitro enzyme inhibition and computational modeling only. No animal or human blood pressure studies conducted. The peptide's bioavailability after oral consumption is unknown.
When this study was published
Published in 2024 in Food Chemistry, a leading journal for food bioactives and functional food research.
The bigger picture
This study exemplifies the convergence of computational screening with food science. Rather than randomly testing thousands of protein fragments, QSAR modeling dramatically narrows the search. The exceptional stability of PLITT under food processing conditions (heat, pH, salt) is particularly notable — many bioactive peptides lose activity during cooking or manufacturing. If PLITT survives digestion equally well, it could be a practical functional food ingredient.
Questions still open
- Does PLITT survive gastrointestinal digestion and maintain its ACE-inhibitory activity after absorption?
- What quantity of mackerel or supplemental PLITT would a person need to consume to achieve a meaningful blood pressure reduction?
- Could PLITT be combined with other food-derived ACE inhibitors for a synergistic effect?
Common questions
Could eating mackerel lower my blood pressure?
How does a QSAR model find peptides?
Read the original research
The novel angiotensin-I-converting enzyme inhibitory peptides from Scomber japonicus muscle protein hydrolysates: QSAR-based screening, molecular docking, kinetic and stability studies.
Food chemistry, 447, 138873
Citation
Wang, Baobei; Zhang, Hui; Wen, Yuxi; Yuan, Wenwen; Chen, Hongbin; Lin, Luan; Guo, Fengxian; Zheng, Zong-Ping; Zhao, Chao. (2024). The novel angiotensin-I-converting enzyme inhibitory peptides from Scomber japonicus muscle protein hydrolysates: QSAR-based screening, molecular docking, kinetic and stability studies.. Food chemistry, 447, 138873. https://doi.org/10.1016/j.foodchem.2024.138873